Problem: Simplify the following expression: $k = \dfrac{30c}{20a + 10} + \dfrac{20b}{20a + 10}$ You can assume $a,b,c \neq 0$.
Solution: Since the expressions have the same denominator we simply combine the numerators: $k = \dfrac{30c + 20b}{20a + 10}$ The numerator and denominator have a common factor of $10$, so we can simplify $k = \dfrac{3c + 2b}{2a + 1}$